Touch sensor firearm safety system

ABSTRACT

A firearm safety system prevents an unintentional discharge of a firearm. A touch sensor is located on a front surface of the firearm trigger and has a conductive touch pad for sensing contact by a user of the firearm. A touch sensing electronic circuit is coupled to the conductive touch pad and trigger and prevents the firearm from discharging if contact with the conductive contact pad is not sensed. Additionally, the safety system can be configured to conserve battery power of electronic firearms by providing a signal to wake-up the system controller.

CROSS REFERENCE TO RELATED APPLICATIONS

The present patent application is a formalization of a previously filed, co-pending provisional patent application entitled “Touch Sensor Firearm Safety System,” filed Nov. 12, 2004, as U.S. Patent Application Ser. No. 60/627,636 by the inventor named in this patent application. This patent application claims the benefit of the filing date of the cited provisional patent application according to the statutes and rules governing provisional patent applications, particularly 35 USC § 119(e)(1) and 37 CFR §§ 1.78(a)(4) and (a)(5). The specification and drawings of the provisional patent application are specifically incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to firearm safety devices and, more particularly, to firearm safety devices having touch sensors for allowing actuation of the firing mechanism.

BACKGROUND OF THE INVENTION

Historically, manufacturers of firearms have developed safety systems that help prevent unintentional discharge of firearms. The 1911 grip safety is an example of such a safety system. It requires the shooter to depress the grip safety sufficiently before the firearm can be fired. Thus an unintentional trigger pull that could occur from dropping or other mishandling of the firearm would not allow the firearm to fire because the grip safety would have to be depressed also. The Savage AccuTrigger is another example of such a safety system. The AccuTrigger is essentially a trigger within a trigger. The main trigger that fires a round of ammunition cannot be pulled until the pre-trigger is pulled and the main trigger is allowed to release the sear. Both of these safety systems provide some additional protection from unintentional discharge of the firearm; however, they are not transparent to all shooters. In the case of the 1911 grip safety, if the grip safety is not properly gripped, it will not be depressed sufficiently to allow the firearm to be fired. Both safety systems require a lever other than the trigger to be displaced a distance before a trigger pull fires the firearm.

U.S. Pat. No. 6,694,963 describes a trigger system that uses a touch sensor as the trigger for a paintball gun. Though this may be an acceptable trigger system for a paintball gun it is not acceptable for a firearm. This trigger system would cause the gun to fire even with an unintentional touch of the trigger or when the user is trying to find the trigger so that he can pull it. Furthermore, the touch trigger circuit only senses initial touching and cannot tell if the user continues to touch the trigger.

U.S. Pat. No. 4,970,819 describes using pressure sensing grip sensors to determine if the gripping pattern matches the pattern of an authorized user of the firearm. That is, it suggests using the pattern of how the authorized user grips the firearm as a means of recognizing him. U.S. Pat. Nos. 6,286,242 and 6,321,478 discuss using grip sensors as a means of sensing a user's intent to fire a firearm. In addition, the idea of using a grip sensor to wake up a system controller is discussed. All of these prior inventions use pressure sensors as grip sensors. This introduces the added complexity that different users do not necessarily apply pressure to the same area of a firearm grip. This has been addressed by using an array of pressure sensors to work as the grip sensor. The array of pressure sensors adds cost and complexity to the system. Users do not necessarily apply the same amount of pressure to the grip when they intend to fire a firearm.

The inventive system eliminates the need for displacement of the safety device and only requires the shooter to contact or touch sensors to show intent to fire. The sensing area of the touch sensors can be made sufficiently large to allow for different size hands and styles of holding the firearm to still allow firing of the firearm.

The inventive safety system is more easily implemented on a firearm that fires electronically initiated ammunition. However, the use of electromechanical devices such as solenoids or piezoelectric actuators can allow the safety system to work with systems that fire percussion primed ammunition.

SUMMARY OF THE INVENTION

The present invention is directed to a supplemental firearm safety system intended to prevent unintentional discharge of a firearm. The inventive safety system can utilize one or more touch sensors. The sensor or sensors are required to be contacted by the shooter in order to enable the firearm to fire. The touch sensor or sensors can be located in such a way that a shooter would normally touch or contact the sensor or sensors when he intends to fire the firearm. Thus, the shooter would not be required to perform any special operations to enable the use of the firearm and the safety system would be largely transparent to the shooter. The trigger bow area of the firearm is a potential location for touch sensors. This safety system can function as a secondary safety in addition to the traditional safety button or switch.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is better understood by reading the following detailed description of the invention in conjunction with the accompanying drawings.

FIG. 1 illustrates an exemplary embodiment of the touch sensor firearm safety system of the present invention.

FIG. 2 illustrates an exemplary touch sensing circuit design that can be used in the present invention.

FIG. 3 illustrates an alternate exemplary embodiment of the touch sensor firearm safety system of the present invention.

FIG. 4 illustrates an exemplary embodiment showing the touch sensor(s) output signal(s) being supplied as an input, along with other inputs, to the system controller which determines if and when to generate a fire pulse based on the inputs.

FIG. 5 illustrates another exemplary touch sensing circuit design that can be used in the present invention.

FIG. 6 illustrates an exemplary embodiment in which a second touch pad is located on a butt plate of a long gun.

FIG. 7 illustrates an exemplary embodiment in which a second touch pad is located on a grip of a firearm.

DESCRIPTION OF THE INVENTION

The following description of the invention is provided as an enabling teaching of the invention in its best, currently known embodiment. Those skilled in the relevant art will recognize that many changes can be made to the embodiments described, while still obtaining the beneficial results of the present invention. It will also be apparent that some of the desired benefits of the present invention can be obtained by selecting some of the features of the present invention without utilizing other features. Accordingly, those who work in the art will recognize that many modifications and adaptations to the present invention are possible and may even be desirable in certain circumstances and are a part of the present invention. Thus, the following description is provided as illustrative of the principles of the present invention and not in limitation thereof, since the scope of the present invention is defined by the claims.

As illustrated in FIG. 1, an exemplary embodiment of the touch sensor firearm safety system includes a single touch sensor 12 located on the trigger bow 10. The touch sensor sensing area covers most of the front surface of the trigger bow. The touch sensor sensing area is made up of a conductive touch pad 12 that is electronically isolated from the metal trigger 10 and connected by wires or traces to a touch sensing circuit such as illustrated in FIG. 2. A flex circuit with an exposed pad can offer a durable touch sensor that could be adhesively attached to the trigger 10. It is also possible to use conductive paint or foil tape to make a touch pad on top of an insulating coating on the metal trigger. The trigger 10 would not have to be made from metal and, if it was made from a non-conductive material such as a plastic or ceramic, the insulating layer between the trigger 10 and touch pad 12 would not be needed. If a conductive trigger were electrically isolated from the rest of the firearm, the trigger could act as the touch pad. The touch sensor could be implemented on a number of different trigger systems. It would be easiest to implement the sensor on a Zero Displacement Trigger as disclosed in U.S. Pat. Nos. 6,668,700 and 6,651,542, because the wiring would not have to work with moving components. However the touch sensor safety system could also be implemented on an electronic micro-switch trigger as used in Remington Arms Co. M/700 EtronX rifles or on a standard mechanical trigger for a firearm that fires percussion ammunition.

Ideally, the touch sensor firearm safety system can immediately recognize contact from a shooter and will know if and when the shooter releases the trigger. The touch trigger described in U.S. Pat. No. 6,694,963 only recognizes touch but does not know when, or if, the touch is released. The touch sensor safety system of the present invention requires the touch sensor to sense whether or not a shooter is simultaneously contacting the touch pad before allowing a trigger pull to initiate firing a round of ammunition. This eliminates unintentional discharges caused by drops or other jarring events that might cause a perceived trigger pull. If the same circuit described in U.S. Pat. No. 6,694,963 was used, the best that could be done is to allow a window of time from contacting the touch pad during which the firearm is allowed to initiate firing when the trigger is pulled or appears to be pulled. This would still allow for the possibility of a drop-induced trigger pull to initiate firing of the firearm if the drop occurred within the time window starting from when the shooter touches the touch sensor. In addition, this system may not allow a legitimate trigger pull to initiate firing a firearm if the shooter takes too long (i.e., longer than the allotted window of time) to pull the trigger.

One exemplary touch sensing circuit design that can be used with the touch sensor firearm safety system is shown in FIG. 2. The LM555 is a timer integrated circuit (IC) for generating accurate time delays that is available from National Semiconductor Corporation. This IC device is not limiting in any way, and any suitable IC timer device could be used in its place. In the present invention, the LM555 timer is used to generate a 30 Hz square wave when configured as shown. The 30 Hz square wave is supplied to the movable contact of a one megaohm potentiometer. One fixed end of the potentiometer is attached to the CLK pin of a latch to give the latch its required 30 Hz clock signal. The other fixed end of the potentiometer is connected to the touch pad and D pin of the latch. The latch used in the circuit design shown in FIG. 2 is a Texas Instruments SN74AC74N, dual positive triggered D-type flip flop. The use of this latch should not be considered restrictive since those skilled in the art will realize that other devices could be used to perform the same function.

FIG. 2 shows two separate latches that are labeled as 74AC74N. These latches are both actually half of the same part and are only separated schematically to simplify the diagram for the optional Touch Pad #2 and supporting electronics. If more than two touch pads were desired, additional latches would be required. If the touch pad is not being touched, then the signal going into the latch D pin is high. If the touch pad is being touched then the signal going to the latch D pin will go low. The latch will set the latch Q pin to the same voltage level as the signal supplied to the latch D pin at a 30 Hz frequency. The latch Q pin supplies a signal to a system controller for use in determining if firing is allowable when the trigger is pulled.

In addition to providing an additional safety from unintentional discharge of a firearm, the touch sensor firearm safety system can be used to conserve the battery life of the battery powering the firearm electronics. This battery life savings can be obtained in several different ways. A first way is that a low signal to the system controller signals the system controller and the rest of the electronic system to wake-up. A second way would be to provide a signal to the system controller to charge the capacitor used to provide the firing pulse needed to fire electronically-primed ammunition, or to energize a solenoid or other actuator used to release or propel a firing pin to initiate percussion-primed ammunition. The former way would provide the most battery life savings but could introduce too much of a delay before the system would be capable of firing under some circumstances. The latter way would provide some battery life savings but would reduce the amount of delay before the system would be capable of firing. This is an improvement over the wake-up feature of U.S. Pat. No. 6,286,242 because it does not wake up or charge the capacitor until just before the user intends to fire the firearm (i.e., the user has started to pull the trigger). It is normal for shooters to handle firearms by the grip areas even when they have no intent of firing the firearm. However, it is not normal, or it is at least unsafe, to touch the trigger until intending to fire a firearm. This could allow additional energy savings because of the elimination of false or unneeded wake-ups.

It should be obvious that minor deviations from the above described exemplary embodiment can be implemented without deviating from the spirit and scope of the invention. One such contemplated alternate exemplary embodiment is illustrated in FIG. 3. This figure depicts a trigger 10 with a touch sensor that has two touch pads 14, 16. In such an exemplary embodiment, it would be required for the shooter to touch both touch pads 14, 16 simultaneously. This could help further eliminate unintentional discharges associated with accidentally pulling the trigger on a light trigger pull gun because the finger would have to be fully in the trigger guard in order to make contact with both touch pads. FIG. 3 shows the two touch pads 14, 16 positioned side by side. Other relative orientations of such devices would work but may overly restrict the allowable positioning of the shooter's finger eliminating the transparency of the safety system to the user.

Many alternative embodiments exist for safety systems that have a second touch pad. The second touch pad does not have to be located on the trigger itself, but does need to be located in proximity to where the shooter would contact it during normal use. Some of the alternative locations for the second touch pad include the grip area 20 of a firearm as illustrated in FIG. 7 or the recoil pad or butt plate 18 of a long gun as illustrated in FIG. 6. These alternative locations for the second touch pad would be more complicated to implement since they would require electronic communication between the stock and the system controller.

The touch sensing circuit shown in FIG. 2 is one exemplary circuit that could be used to create a touch sensor. Other circuits have been contemplated but for simplicity have not been shown. The changes to the exemplary circuit can be as simple as changing to a higher frequency square wave than the 30 Hz square wave generated by the timer integrated circuit chip shown in FIG. 2, or could involve a more complex circuit design. Additionally, much of the circuit shown in FIG. 2 could be replaced by currently available integrated circuits. Quantum Research Group's QTouch™ QT220, two channel touch sensor IC, is an example of such an integrated circuit. Other integrated circuits are available that provide different numbers of independent channels.

FIG. 4 shows how the touch sensor(s) output 28 is provided as an input to a system controller 30. The system controller 30 uses this information along with information received from the safety switch 24 and trigger pull detection system 26 to determine if and when to provide a fire pulse 32 to fire a round of ammunition electrically or electro-mechanically. Additionally, this input from the touch sensor 22 can be used to wake-up the system controller 30. The input from the touch sensor 22 could also be used to signal the system controller 30 to perform some other function such as charging a bulk capacitor used to store energy needed for the fire pulse 32 that needs to be completed prior to the firearm being ready to fire. Both of these offer a means to conserve battery power.

The touch sensing circuit shown in FIG. 5 is an exemplary circuit that could be used to create a touch sensor for a percussion firearm that was not equipped with a system controller. The circuit is very similar to the one that is shown in FIG. 2 except it is only equipped with one touch pad and the Q pin signal of the latch is not sent to a microcontroller or system controller but to an additional circuit. The touch sensor signal from latch pin Q is sent through an inverter U5:A, and resistor R1 to switch U3. When the signal from the Q pin of the latch goes from logic high to logic low, the switch U3 switches one side of a solenoid coil to power the solenoid so as to remove a physical block that was preventing the firearm from being fired. Thus, when the touch sensor senses touch to the touch pad, firing the firearm is enabled. The inverter could be eliminated if the signal from the Q pin was used instead of the Q pin as would be understood by those skilled in the art.

Diode D1 is a 1N4004 diode and is connected across the solenoid as shown to protect switch U3 from damaging voltage spikes that occur once the switch U3 is disabled. The circuit depicts switch U3 as an International Rectifier IRF3707 N-channel MOSFET. Switch U3 could also be another device suitable for this purpose, such as a bipolar transistor, an electro-mechanical relay, or a solid state relay as will be understood by those skilled in the art.

The corresponding structures, materials, acts and equivalents of all means plus function elements in any of the claims below are intended to include any structure, material, or acts for performing the function in combination with other claim elements as specifically claimed.

Those skilled in the art will appreciate that many modifications to the exemplary embodiments are possible without departing from the spirit and scope of the present invention. In addition, it is possible to use some of the features of the present invention without the corresponding use of the other features. Accordingly, the foregoing description of the exemplary embodiments is provided for the purpose of illustrating the principles of the present invention and not in limitation thereof since the scope of the present invention is defined solely by the appended claims. 

1. A firearm safety system including a trigger, comprising: a trigger bow; a touch sensor located on a surface of the trigger bow, the touch sensor including a conductive touch pad that is isolated electrically from the firearm; and an electronic circuit operationally coupled to the touch sensor and activated by a user's contact with the touch pad.
 2. The firearm safety system of claim 1 wherein the electronic circuit provides a wake-up signal to a system controller when the touch pad is touched.
 3. The firearm safety system of claim 1 wherein the electronic circuit provides a logic signal to a system controller that is used to determine if firing can be initiated when the trigger is pulled.
 4. A trigger safety system for a firearm comprising: a touch sensor comprising a conductive touch pad for sensing contact by a user; an electronic circuit coupled to the touch sensor and the trigger for controlling activation of a firing mechanism of the firearm.
 5. A firearm safety system including a touch sensor comprising: at least one conductive touch pad to sense a touch; an electronic circuit operationally coupled to the conductive touch pad and activated by a user's contact with the at least one touch pad.
 6. The firearm safety system of claim 5 wherein the touch pad is located on a surface of a trigger bow.
 7. The firearm safety system of claim 5 wherein the touch sensor comprises two touch pads.
 8. The firearm safety system of claim 7 wherein one conductive touch pad is located on a surface of a trigger bow.
 9. The firearm safety system of claim 7 wherein both conductive touch pads are located on a surface of a trigger bow.
 10. The firearm safety system of claim 9 wherein the conductive touch pads are positioned side by side along a length of the trigger bow.
 11. The firearm safety system of claim 5 wherein the electronic circuit includes a system controller.
 12. The firearm safety system of claim 11 wherein the safety system is configured to conserve battery power.
 13. The firearm safety system of claim 12 wherein the battery power is conserved by allowing the system controller to remain in a sleep mode until the touch pad is touched.
 14. The firearm safety system of claim 12 wherein energy is conserved by not charging a bulk capacitor that is used to store the energy needed to fire the round of ammunition until the touch pad is touched.
 15. The firearm safety system of claim 5 wherein the electronic circuit includes a solenoid coil of that is used to block the firing of a firearm until the solenoid is energized.
 16. The firearm safety system of claim 8 wherein a second touch pad is located on a grip area of the firearm.
 17. The firearm safety system of claim 8 wherein a second touch pad is located on either a recoil pad or butt plate of a long gun.
 18. The firearm safety system of claim 5 further comprising a system controller to charge a capacitor to provide a firing pulse to discharge electronically-primed ammunition.
 19. The firearm safety system of claim 5 further comprising an actuator to release or propel a firing pin for firing of percussion-primed ammunition. 